The combustion of sulfur bearing fossil fuels such as coal engenders the creation of sulfur oxides and the reduction of these sulfur oxides has been established as the goal of a variety of legislation. It has thus become an accepted practice to provide as appropriate sulfur oxide removal systems integrated into fossil fuel-fired power generation systems to remove sulfur oxides from the flue gas combustion products.
One known sulfur oxide removal system is a so-called dry sulfur oxide scrubbing system comprising a chamber through which flue gas is flowed and in which a sulfur oxide absorbent is delivered into contact with the flue gas to achieve a reaction process with the sulfur oxide in the flue gas. A resultant product of this reaction process is the formation of a dry particulate which is amenable to separation from the flue gas via, for example, a dry particulate collection assembly. Typically, flue gas is passed through an air preheater prior to its contact with the sulfur oxide absorbent for the purpose of effecting a transfer of heat from the flue gas to incoming air ultimately destined for consumption in the combustion process. Moreover, the flue gas generally retains sufficient heat content, in spite of the upstream heat exchange at the air preheater, to permit the delivery of the sulfur oxide absorbent into contact with the flue gas by means of a slurry, as the liquid fraction of the slurry will be vaporized by the flue gas.
It may be noted that there is today a heightened awareness that the disposal of certain products and by-products of the combustion process in one form may be preferred to the disposal of the same product or by-product in another form. One such by-product is waste water used or created during the combustion process and its ancillary processes. The disposal of this waste water, which hereafter shall be taken to mean any liquid composition of predominantly water which is produced by, or remains from, the various processes which occur in a fossil fuel-fired power generation system including its combustion and heat exchanges process, can present a challenge, particularly if, in a given situation, it is preferred that the waste water not be disposed of in its liquid form.
Accordingly, the need exists for realistic opportunities for the disposal of waste water accumulated in a fossil fuel-fired power generation system in a manner which minimizes the impact on the efficiency of the system.